forked-skill-execution-with-isolated-context

forked-skill-execution-with-isolated-context is a skill for Claude Code, Codex from ychampion/cskill-agents. It costs 34 tokens per session (511 once invoked), scanned A, original, MIT.

A way to run a skill command in a separate helper agent with its own limits and state. The main agent receives the helper's final result without sharing its working session.

In plain words
What is it for?
Running slash commands marked for separate execution, especially when their progress, tool use, and cleanup must be tracked independently.
Why use it?
It prevents one skill run from consuming or changing the main agent's context. It also gives the separate run its own tracking and lifecycle.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Good fit Running slash commands marked for separate execution, especially when their progress, tool use, and cleanup must be tracked independently.

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Install with agentmods
npx agentmods add skills/ychampion/cskill-agents/forked-skill-execution-with-isolated-context
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add ychampion/cskill-agents --skill forked-skill-execution-with-isolated-context
Clone the repo
git clone --depth 1 https://github.com/ychampion/cskill-agents

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for forked-skill-execution-with-isolated-context

README.md
[![agentmods](https://agentmods.dev/badge/skills/ychampion/cskill-agents/forked-skill-execution-with-isolated-context/github.svg)](https://agentmods.dev/skills/ychampion/cskill-agents/forked-skill-execution-with-isolated-context)
Your own site
<a href="https://agentmods.dev/skills/ychampion/cskill-agents/forked-skill-execution-with-isolated-context"><img src="https://agentmods.dev/badge/skills/ychampion/cskill-agents/forked-skill-execution-with-isolated-context/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for forked-skill-execution-with-isolated-context

Your own site · 80×15
<a href="https://agentmods.dev/skills/ychampion/cskill-agents/forked-skill-execution-with-isolated-context"><img src="https://agentmods.dev/badge/skills/ychampion/cskill-agents/forked-skill-execution-with-isolated-context.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 511 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00034 $0.00511
Opus 5 $0.00017 $0.00255
Sonnet 5 $0.00007 $0.00102
Haiku 4.5 $0.00003 $0.00051

Measured 6d ago against content hash ad71b62ac8ec, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

forked-skill-execution-with-isolated-context scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/claude-code/skills/forked-skill-execution-with-isolated-context/SKILL.md · 28 lines

How it starts

The opening of the file, as written. The whole thing — 28 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SKILL: Forked Skill Execution With Isolated Context

Domain: agentic-loop Trigger: Load this skill when SkillTool needs to wrap a prompt command marked with context:'fork' into a sub-agent run that cannot touch the parent session state. Source Pattern: Distilled from reviewed subagent orchestration, isolation, and lifecycle implementations.

Core Method

Merge the command metadata (model, effort, telemetry tags) into a cloned agent definition, record the forked skill invocation, and run the skill prompt through run agent so it executes in a dedicated loop with its own agent id. Buffer the streaming messages, emit progress when tool content appears, and once run agent completes extract and return a clean result string after releasing the temporary message buffer and invoked-skill state. The parent context still honors overrides (allowed tools, effort, model suffix) via context modifier, while telemetry uses sanitized names and agent IDs so the forked execution is auditable separately.

Key Rules

  • Only fork a skill when command context 'fork'; treat every other slash command as inline to avoid extra sub-agents.
  • Feed the prepared prompt messages, modified get app state, and context options tools into run agent, tagging emitted messages with tool use id so downstream renderers can tie progress to this tool call.
  • Emit progress events for every normalized message that contains tool_use/tool_result content so UI components can show streaming updates even though SkillTool owns the loop.
  • After completion, clear invoked skills for the forked agent, compute result text defensively, and include the agent id in the returned tool result so callers can correlate logs or diagnostics.

Example Application

If a CLI-style review skill needs to spawn its own interpreter to run analysis on a repo snapshot, mark it as context:'fork', let SkillTool merge its effort override, and rely on this method to keep the review sub-agent separate while streaming progress back to the caller.

Read the full file on GitHub · 28 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 28 lines · 34 tokens per session scan A ad71b62ac8ec

Subscribe to this mod's changes

forked-skill-execution-with-isolated-context is a skill published in the GitHub repository ychampion/cskill-agents (36 stars, last pushed 5mo ago), licensed MIT. It adds 34 tokens to every session and 511 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.